[erlang-questions] Resisting "noconnection" / Remote termination of nodes

Olivier BOUDEVILLE <>
Tue Apr 24 13:52:18 CEST 2012


Hi,

For a more controlled overall termination of a distributed application, I 
try to shutdown synchronously a series of nodes, as properly and as in 
parallel as possible, in a non-OTP program. I imagine that using '[ 
rpc:cast( N, erlang, halt, [] ) || N <- MyTargetNodes ]' and then waiting 
for them to be terminated is the best approach for that.

As I want now these terminations to be synchronous (i.e. I want my 
terminate function to return only when all nodes are down for sure), I 
used to rely on checking their termination using net_adm:ping/1 (waiting 
for pong to become pang), but kept on getting (systematically) 
'noconnection' errors (exceptions?), which do not seem to be catchable (at 
least not with a 'try .. catch T:E ->.. end' clause). This happens as soon 
as there is at least one node (which happens to be on the same host - of 
course it is not the local node from which that rpc:cast is triggered) to 
halt.

I switched to looping on 'lists:member( Nodename, nodes() )' instead of 
ping (in both case with a proper waiting between checks), but I still get 
'noconnection' errors. It looks like 'noconnection' is VM-level? As 
expected, commenting-out the rpc:cast/3 never leads to 'noconnection'. 

I feel I would need something like net_kernel:unconnect_node/1.

My question now: how to deal gracefully with such a synchronous node 
shutdown and to resist to the (intended) loss of node(s)? 

Thanks in advance for any hint!
Best regards,

Olivier.
---------------------------
Olivier Boudeville

EDF R&D : 1, avenue du Général de Gaulle, 92140 Clamart, France
Département SINETICS, groupe ASICS (I2A), bureau B-226
Office : +33 1 47 65 59 58 / Mobile : +33 6 16 83 37 22 / Fax : +33 1 47 
65 27 13



Ce message et toutes les pièces jointes (ci-après le 'Message') sont établis à l'intention exclusive des destinataires et les informations qui y figurent sont strictement confidentielles. Toute utilisation de ce Message non conforme à sa destination, toute diffusion ou toute publication totale ou partielle, est interdite sauf autorisation expresse.

Si vous n'êtes pas le destinataire de ce Message, il vous est interdit de le copier, de le faire suivre, de le divulguer ou d'en utiliser tout ou partie. Si vous avez reçu ce Message par erreur, merci de le supprimer de votre système, ainsi que toutes ses copies, et de n'en garder aucune trace sur quelque support que ce soit. Nous vous remercions également d'en avertir immédiatement l'expéditeur par retour du message.

Il est impossible de garantir que les communications par messagerie électronique arrivent en temps utile, sont sécurisées ou dénuées de toute erreur ou virus.
____________________________________________________

This message and any attachments (the 'Message') are intended solely for the addressees. The information contained in this Message is confidential. Any use of information contained in this Message not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval.

If you are not the addressee, you may not copy, forward, disclose or use any part of it. If you have received this message in error, please delete it and all copies from your system and notify the sender immediately by return message.

E-mail communication cannot be guaranteed to be timely secure, error or virus-free.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://erlang.org/pipermail/erlang-questions/attachments/20120424/ee9f1b58/attachment.html>


More information about the erlang-questions mailing list